The timing of rifting events in the easternmost Mediterranean: U-Pb dating of zircons from volcanic rocks in the Levant margin

Abstract

ABSTRACT The Levant basin, at the easternmost Mediterranean, formed during the opening of the Neo-Tethys at Permian to Jurassic times, as recorded by subsidence and magmatism along its SE passive margin. While the subsurface extensional structure was reconstructed in detail, the spatial and temporal distribution of igneous activity is not well known. Here we present new SIMS U-Pb dating of zircons from rifting related volcanic sequences recovered from four deep boreholes in the Levant margin of coastal Israel. The Asher volcanics, a deeply buried 2.5 km thick basaltic sequence, which accumulated within fault-bounded basin, was previously dated by K-Ar and Ar-Ar to early Jurassic times. Zircons (n=46) separated from the bottom and top of the volcanic sequence yielded 206±2 Ma and 205 to 202 Ma, respectively, indicating that Asher volcanics are of Late Triassic (Rhaetian) age. Zircon xenocrysts indicate Permian (289±2 Ma) felsic magmatism. Rifting activity in the Levant margin included several Permian-Triassic pulses of faulting and subsidence, with a prolonged magmatism-bearing rifting event at Late Carnian to Rhaetian times (~230-201 Ma). Pulsed rifting is also indicated in the conjugate, northern, margin of the southern Neo-Tethys, and the timing of subsidence and magmatic pulses well correlate to the Levant margin.